Methods for making a sensitive resonating beam accelerometer

Abstract

A method of making a resonating beam accelerometer (RBA). In an example process, a proof mass device and resonators are created from a quartz material. A direct bond is formed between the proof mass and the resonators by applying a predefined amount of pressure at a predefined temperature for a predefined amount of time. One or more damping plates are created from a quartz material. A direct bond is formed between the damping plates and the proof mass device. The proof mass device is created by applying a predefined amount of pressure at pressure at temperature to two bases, two proof mass portions, and a flexure. The proof mass bases are on opposite sides of the flexure. The proof mass portions are on opposite sides of the flexure. A gap is present between the proof mass bases and the proof mass portions.

Description

PRIORITY CLAIM[0001]This application is a continuation of U.S. patent application Ser. No. 12 / 751,157 filed on Mar. 31, 2010 and is incorporated herein by reference.GOVERNMENT INTEREST[0002]The invention described herein was made in the performance of work under U.S. Government Contract No. FA9453-05-C-0241 awarded by Air Force Research Laboratories. The Government may have rights to portions of this invention.BACKGROUND OF THE INVENTION[0003]The sensitivity of an accelerometer can be degraded by creep of bonded joints. It can also be degraded by a difference in the coefficient of thermal expansion (CTE) between the bonding solder or glue and the bonded pieces.[0004]The resonators and damping plates are typically attached employing either solder or glue. Glue, and to a lesser degree solder, may creep (the tendency of a solid material to slowly move or deform under the influence of stress), thus degrading the sensitivity of the accelerometer.[0005]In addition, the sensitivity of an a...

AI Technical Summary

Benefits of technology

This approach results in a sensitive resonating beam accelerometer with improved stability and accuracy by eliminating creep and thermal expansion issues, ensuring consistent performance and reducing the risk of hinge failure.

Problems solved by technology

Glue, and to a lesser degree solder, may creep (the tendency of a solid material to slowly move or deform under the influence of stress), thus degrading the sensitivity of the accelerometer.

Machining the hinge can introduce microcracking in the hinge, resulting in loss of accelerometer sensitivity and / or hinge failure.

Once again, creep of the solder or glue, as well as the CTE mismatched between the solder or the glue and the proof mass material, will degrade sensitivity.

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